Danbury Hospital said it has sold its on-site pharmacy to national retailer Walgreens as the hospital looks to cut ownership ties with a financial liability, regulatory filings show.

The hospital, which is part of the Western Connecticut Health Network, said its Danbury Pharmacy unit has been financially challenged for some time, "lacking the volume and purchasing power of major national chains," according to a document filed with the state's Office of Healthcare Access.

The hospital also said changes in payment plans, particularly with Medicaid and Hartford health insurer Aetna, have also had a negative impact on the pharmacy's financial viability.